COBEM99

S18 Processos Mecânico-Metalúrgicos

Title:

ESTUDO DA INSTABILIDADE DO CORDÃO EM SOLDAGEM MIG PULSADA

Summary :

STUDY OF BEAD INSTABILITY IN PULSED MIG WELDING ABSTRACT. THE MIG PULSED PROCESS IN AUTOMATED WELDINGS IN GROOVES HAS BEEN PRESENTING PROBLEMS AS MELT AND PENETRATION LACK, BESIDES BEAD INSTABILITY. THE OBSERVED INSTABILITY IS CHARACTERIZED BY A WELD BEAD DEVIATION FOR THE WALLS OF THE GROOVE, IMPEDING THE CONTINUOUS WELDING OF LONG SPACES OF WELDS. PRELIMINARIES TESTS SHOWED THE INFLUENCE OF SOME OPERATIONAL PARAMETERS ON THE BEAD STABILITY. AMONG THEM: TORCH INCLINATION, TRAVEL SPEED, CURRENT AVERAGE, SHIELDING GAS, GROOVE GEOMETRY AND ARC LENGTH. THE ANALYSIS OF THESE PARAMETERS SHOWED THAT THE DEPOSITED METAL VOLUME BY LENGTH WELDED IS ONE OF THE MAIN FACTORS THAT INFLUENCE THE BEAD STABILITY. THE AIM OF THIS WORK IS TO CHECK THE VALIDITY OF A THEORETICAL MODEL THAT RELATES THE DEPOSITED METAL VOLUME BY UNIT OF LENGTH OF THE BEAD WITH SOME OPERATIONAL PARAMETERS OF THE PROCESS, IN FUNCTION OF BEAD GEOMETRIC STABILITY. THE RESULTS SHOWED THAT THE THEORETICAL MODEL IN SPITE OF DEMONSTRATING CERTAIN VALIDITY, IT IS LIMITED, BECAUSE THIS CONSIDERS THAT ONLY THE DEPOSITED METAL VOLUME BY WELDED LENGTH INFLUENCES THE BEAD INSTABILITY, DESPISING THE INFLUENCE OF THE OTHER WELDING PARAMETERS, THAT DEMONSTRATED IN AN ADDITIONAL TEST, ITS INFLUENCE ON THE BEAD STABILITY. KEYWORDS: PULSED MIG, MODEL, BEAD INSTABILITY, SHIELDING GAS

Author :

Ferraresi, Valtair Antonio
Pereira, Warley Augusto

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